// ASM: a very small and fast Java bytecode manipulation framework
// Copyright (c) 2000-2011 INRIA, France Telecom
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//
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// modification, are permitted provided that the following conditions
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//    notice, this list of conditions and the following disclaimer in the
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package org.springframework.asm;

/**
 * A visitor to visit a Java module. The methods of this class must be called in the following
 * order: ( {@code visitMainClass} | ( {@code visitPackage} | {@code visitRequire} | {@code
 * visitExport} | {@code visitOpen} | {@code visitUse} | {@code visitProvide} )* ) {@code visitEnd}.
 *
 * @author Remi Forax
 * @author Eric Bruneton
 */
public abstract class ModuleVisitor {
	/**
	 * The ASM API version implemented by this visitor. The value of this field must be one of {@link
	 * Opcodes#ASM6} or {@link Opcodes#ASM7}.
	 */
	protected final int api;

	/**
	 * The module visitor to which this visitor must delegate method calls. May be {@literal null}.
	 */
	protected ModuleVisitor mv;

	/**
	 * Constructs a new {@link ModuleVisitor}.
	 *
	 * @param api the ASM API version implemented by this visitor. Must be one of {@link Opcodes#ASM6}
	 *            or {@link Opcodes#ASM7}.
	 */
	public ModuleVisitor(final int api) {
		this(api, null);
	}

	/**
	 * Constructs a new {@link ModuleVisitor}.
	 *
	 * @param api           the ASM API version implemented by this visitor. Must be one of {@link Opcodes#ASM6}
	 *                      or {@link Opcodes#ASM7}.
	 * @param moduleVisitor the module visitor to which this visitor must delegate method calls. May
	 *                      be null.
	 */
	public ModuleVisitor(final int api, final ModuleVisitor moduleVisitor) {
		if (api != Opcodes.ASM7 && api != Opcodes.ASM6) {
			throw new IllegalArgumentException("Unsupported api " + api);
		}
		this.api = api;
		this.mv = moduleVisitor;
	}

	/**
	 * Visit the main class of the current module.
	 *
	 * @param mainClass the internal name of the main class of the current module.
	 */
	public void visitMainClass(final String mainClass) {
		if (mv != null) {
			mv.visitMainClass(mainClass);
		}
	}

	/**
	 * Visit a package of the current module.
	 *
	 * @param packaze the internal name of a package.
	 */
	public void visitPackage(final String packaze) {
		if (mv != null) {
			mv.visitPackage(packaze);
		}
	}

	/**
	 * Visits a dependence of the current module.
	 *
	 * @param module  the fully qualified name (using dots) of the dependence.
	 * @param access  the access flag of the dependence among {@code ACC_TRANSITIVE}, {@code
	 *                ACC_STATIC_PHASE}, {@code ACC_SYNTHETIC} and {@code ACC_MANDATED}.
	 * @param version the module version at compile time, or {@literal null}.
	 */
	public void visitRequire(final String module, final int access, final String version) {
		if (mv != null) {
			mv.visitRequire(module, access, version);
		}
	}

	/**
	 * Visit an exported package of the current module.
	 *
	 * @param packaze the internal name of the exported package.
	 * @param access  the access flag of the exported package, valid values are among {@code
	 *                ACC_SYNTHETIC} and {@code ACC_MANDATED}.
	 * @param modules the fully qualified names (using dots) of the modules that can access the public
	 *                classes of the exported package, or {@literal null}.
	 */
	public void visitExport(final String packaze, final int access, final String... modules) {
		if (mv != null) {
			mv.visitExport(packaze, access, modules);
		}
	}

	/**
	 * Visit an open package of the current module.
	 *
	 * @param packaze the internal name of the opened package.
	 * @param access  the access flag of the opened package, valid values are among {@code
	 *                ACC_SYNTHETIC} and {@code ACC_MANDATED}.
	 * @param modules the fully qualified names (using dots) of the modules that can use deep
	 *                reflection to the classes of the open package, or {@literal null}.
	 */
	public void visitOpen(final String packaze, final int access, final String... modules) {
		if (mv != null) {
			mv.visitOpen(packaze, access, modules);
		}
	}

	/**
	 * Visit a service used by the current module. The name must be the internal name of an interface
	 * or a class.
	 *
	 * @param service the internal name of the service.
	 */
	public void visitUse(final String service) {
		if (mv != null) {
			mv.visitUse(service);
		}
	}

	/**
	 * Visit an implementation of a service.
	 *
	 * @param service   the internal name of the service.
	 * @param providers the internal names of the implementations of the service (there is at least
	 *                  one provider).
	 */
	public void visitProvide(final String service, final String... providers) {
		if (mv != null) {
			mv.visitProvide(service, providers);
		}
	}

	/**
	 * Visits the end of the module. This method, which is the last one to be called, is used to
	 * inform the visitor that everything have been visited.
	 */
	public void visitEnd() {
		if (mv != null) {
			mv.visitEnd();
		}
	}
}
